8)Schönlein-Henoch紫斑病

Schönlein-Henoch Purpura

　Schönlein-Henoch紫斑病は毛細血管～細動脈の血管炎に起因し，皮膚症状，腹部症状，関節症状，腎障害を主な兆候とする疾患である．腹部症状の頻度は高く，特に腹痛が多い．本症の内視鏡所見は多彩であり，発赤，紫斑様病変，浮腫，びらん，潰瘍などがみられる．この機序は血管炎により，血管透過性の亢進による滲出・出血が起こり，発赤や紫斑様病変が生じ，さらに血管の障害が高度になると血栓が生じ虚血性変化が起こり，浮腫，びらん，潰瘍が生じると考えられる．十二指腸病変は第2部～第4部に好発し，多発する潰瘍性病変を来すことが多い．胃や大腸では紫斑様の発赤斑が多くみられる．

　Schönlein-Henoch purpura is a disease secondary to vasculitis of capillaries and arterioles. Its major signs are skin symptoms, abdominal symptoms, articular symptoms and kidney disorder. Patients with this disease often experience abdominal symptoms (abdominal pain, in particular). Endoscopically, this disease presents with diverse features, including redness, purpuric lesions, edema, erosion and ulcers. Regarding the mechanism for the onset of this disease, it is thought that vasculitis elevates vascular permeability, leading to effusion, bleeding, redness and purpuric lesions, and that if vascular lesions are severe, thrombi are formed, leading to ischemic changes which can cause edema, erosion and ulcers. Duodenal lesions associated with this disease often develop in the second through to the fourth portions of the duodenum and they frequently assume the form of multip le ulcerative lesions. Red spots, resembling purpura, are often seen on the stomach and large intestine of patients with this condition.